Patiño Sandra, Aalto Tuula, Edwards Alice A, Grace John
Institute of Ecology and Resource Management, The University of Edinburgh, Darwin Building, Mayfield Road, Edinburgh EH9 3JU, UK.
Helsinki Finland.
New Phytol. 2002 May;154(2):429-437. doi: 10.1046/j.1469-8137.2002.00396.x.
• The giant flowers of the parasitic Rafflesia occur in the shade of the forest understorey. They present several characteristics in common with the related species, Rhizanthes lowii, which is a strongly endothermic flower. The possible existence of endothermy in Rafflesia tuan-mudae was investigated here. • The internal and surface temperature of the flowers were continuously monitored with fine thermocouples while radiation fluxes and microclimatic variables were recorded. A computational fluid dynamic model was used to predict the concentrations of CO inside the diaphragm of the flower. • It was found that the internal parts of the flower were maintained a few degrees (1-6 K) above air temperature. It was not possible to account for this temperature rise without postulating a significant internal source of heat. It was concluded that R. tuan-mudae is an endothermic flower that generates a maximum of 50-60 W m of heat in the centre of the column. • The possible role of endothermy, CO and volatiles as elements in the mimicry of the flower to attract pollinating blowflies is discussed and compared with the related species Rhizanthes lowii.
• 寄生植物大王花巨大的花朵生长在森林下层的阴凉处。它们呈现出与相关物种——强吸热性花朵罗氏大花草的几个共同特征。本文对阿诺德大王花中可能存在的吸热现象进行了研究。
• 用精细热电偶持续监测花朵的内部和表面温度，同时记录辐射通量和微气候变量。使用计算流体动力学模型预测花朵隔膜内二氧化碳的浓度。
• 研究发现，花朵内部温度比气温高几度（1 - 6K）。如果不假定存在显著的内部热源，就无法解释这种温度升高现象。研究得出结论，阿诺德大王花是一种吸热性花朵，在花柱中心产生的热量最高可达50 - 60瓦每平方米。
• 讨论了吸热、二氧化碳和挥发性物质作为花朵拟态吸引传粉丽蝇的元素的可能作用，并与相关物种罗氏大花草进行了比较。
